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Been a while since I last made a long-range thread. But this time period looks promising in terms of flow. Let's take a stab at it, shall we? If it doesn't pan out, there's always March . BSR 500mb. I like where that flow is positioned. Right off the coast, maybe a tad too close to land, but hey these aren't specifics. Just the flow. BSR surface. Quite a mess to be honest, but look at the amount of storms there. I guess the energy is there to work with the flow . GFS and FV3-GFS. 300+ hours out so obviously this doesn't matter one bit. Just included for those who like maps. GFS EAR. I like that storm moving out from Japan. Interesting storm trailing it too. Note the tropical system down there too - will be something to watch. GEM EAR. Pretty much same comment as the previous one repeated. GFS northern hemisphere. Note the various small waves across East Asia compared to the flat flow earlier. Will be interesting to watch the chaos it evokes on modeling.
PREFACE Operational model support is important, what do you think? If you say yes, perhaps you will be thinking now that it´s too much of gamble and waste of time and energy to start a thread for a possible storm 14 to 16 days out, with basically zero, or perhaps zero operational guidance support. If you think it´s not important, then perhaps you are thinking that this should be an interesting endeavor, worthy of the time and energy used. Ok. So, let´s continue, shall we? There´s a chance, possibility that a storm may form and grace the region with its blessed weather. All rain? All snow? A mix? Impossible to know. And honestly, there´s the no storm outcome as well. Having that in mind, let us see what we can get from this thread´s time frame only using teleconnections, EPS ensemble data, BSR and a couple of ESRL/PSD products. SUMMARY There exists the possibility during this time frame for a developing area of lower pressures on the East coast (inland or offshore), coming from the eastern GOMEX and SE CONUS area. Another possibility of an area of lower pressures could be in and around the Ohio and Tennessee valleys tracking eastward towards the east coast and ejecting over the Atlantic ocean from somewhere in the Mid-Atlantic region. Both areas of lower pressures could impact the thread´s region with some kind of weather. It´s impossible to exact if this possible storm would track inland, tucked to the coast, just offshore, or be a near miss, in the case of a possible SE CONUS genesis. As for the Ohio and Tennessee valleys possible area of lower pressures, the track is also uncertain, obviously. It may track too far north over NJ, father south or even cut through western NY. What should be noted is that we may have a storm to deal with, as the Holydays near. The data used to try to give some sense of support to this possibility, include, as aforementioned, teleconnections (AO, NAO, EPO, and PNA) from various different sources which include ESRL/PSD, GEFS, EPS and EPS 46 days), the BSR and other ERSL/PSD products. Below, I have illustrated in a simplistic and basic way, the general track areas for the lower pressures that could develop, as described in this summary. Please, take a look: On the next page, we will cover the previously supportive or not so much, mentioned data with images. Let´s start with the BSR. Looking at both the 500mb and surface depictions, there´s seems to be little support for a storm during this time frame, aside from a more noteworthy signal one day earlier on the 18th of December. Perhaps this could be a case in which a storm is delayed or could track in and around the coastal plain. However, acknowledging the BSR data shown for this time frame alone, a storm should cut through western NY. 500mb Surface So, support for a storm exists, but not the kind of storm most would want. Now on to a couple of ESRL/PSD products: These do show some support, as there seems that a trough will be digging and moving towards the east coast. The magnitude of the trough (how amplified and strong), of course, cannot be set now. Ensemble Mean 500mb Height Sea Level Pressure / 1000-500mb Thickness Hence, there is support for a storm as well, albeit, it may not be a powerfully amplified trough and flow. Now we get to the teleconnections from various different sources. They include the AO, EPO, NAO, and PNA. Some of them are not favorable, others are while some are in that highly regarded transition period. First off, we will check the AO. EPS 46 Days EPS GEFS All sources indicate a negative AO. Both the EPS 46 days and the EPS, show the AO closer to neutrality but does not quite make a transition. Negative AO bodes well for colder temperatures over the eastern CONUS. Being that the values are not that negative, it´s possible that the cold air, won´t be as deep or strong. Now, a look at the EPO. EPS 46 Days EPS GEFS All source indicate a positive EPO. They show small positive values and approaching neutrality. However, the do not quite start making the transition. Negative EPO helps keep the eastern CONUS colder. So, this kind of EPO along with the AO, may be saying that there should be cold air in place, but not strong in nature. Now, we check the NAO. EPS 46 Days EPS GEFS All sources indicate a negative NAO transitioning to neutrality and perhaps actually going into positive territory as can be seen on the EPS 46 days data. Negative NAOs support blocking of some sort. A transitioning NAO period is usually good for east coast storms. Now, we get to the PNA. EPS 46 Days EPS GEFS All sources indicate a positive PNA. A positive PNA means ridging over the western US, which in turn helps troughs get established over the eastern CONUS. Now to finalize the teleconnections, below please see the ESRL/PSD. Not quite in range, but we can see that PNA is quite positive, beneficial. The NAO going neutral, perhaps transitioning to negative. If so, it´s beneficial. And the EPO rather positive, not beneficial. In case it gets to neutral or transitions to negative by the time in discussion, that then would be a plus. In short, all in all, we have some good indications that a storm could be in the region during this time frame. And considering all the data discussed, in case a storm that brings snow to the eastern seaboard comes, we should not be surprised. At the very least, we will learn more once again. Whenever you feel the time has come, please join the discussion and possible tracking. Remember, there´s no model support as of now. Have fun! NOTE: The thread date and title will most likely need to be adjusted as we get near the time frame.